Agent and process for drenching skins



Patented Dec. 19, 1933 PATENT OFFICE 1,940,265 AGENT AND raoosss FOR DRENCHING sxms Wilhelm Neugebauer, Wiesbaden-Biebrich, Germany, assignor to Kalle & Co.

Aktiengesellschatt, Wiesbaden-Biebrich, Germany No Drawing. Application January 15, 1932,

Serial No. 1931 3 Claims.

The present invention relates to agents and a process for drenching skins.

Drenching agents containing proteolytic enzymes, for instance those of the pancreas, are already known. The known drenching agents of this kind consist of mixtures of proteinases and aminoand carboxypeptidases, which constituents it was hitherto hardly possible to separate from one another.

The present-invention is based on the discovery that solutions of pancreas proteinases free from peptidases, and particularly from carboxypetidases, constitute drenching agents giving a particularly good drenching effect. The skins drenched with these proteinases and the leathers produced therefrom have, as compared with those drenched with a mixture of pro teinases and peptidases, a more compact and softer touch without, however, being flabby.

The proteinases free from peptidases can be utilized in the same manner as the drenching agents hitherto used. For the neutralization of the alkalinity of the skins coming from the lime liquor, the usual buffering agents may be employed, such as ammonium salts, for instance ammonium sulfate or ammonium chloride, or lactic acid, boric acid, sodium bisulfite or other substances having a similar action. The said agents may be employed in a preliminary bath before the drenching process or alternatively,- particularly in the case of ammonium saltsthey may be applied in the drenching solution itself.

The proteinases free from peptidases, which are utilized in the present ,process; can for instance be obtained according to the process set forth in the British Patent Specification No. 356,638, dated January 31, 1930, in the name of Kalle 81 Co. Aktiengesellschaft.

The following examples illustrate the invention:

1. 0.1 kilo of ammonium chloride and a quantity oi proteinase free from. peptidase obtained from hogs pancreas by the process according to the specification above-mentioned,

586,968, and in Germany January 24,

are dissolved in liters of water. The quantity of enzyme employed is such that 1.0 kilo of gelati'ne after treatment therewith for 1 hour at 37 C., no longer solidify on cooling. 20

kilos of limed, unhaired and rinsed calf skins 50 of normal quality are treated with this solution for 1 hour at about 37 C.

By that time the pelts will have become drenched. After being worked up in the usual manner, they yield a leather of a softer and more compact touch than a leather which has been drenched with the natural mixture of proteinases and peptidases of hogs pancreas.

2. 20 kilosof unhaired goat skins are treated for hour at about 38 C. in a reel with 100 liters of water and 0.2 kilo of a mixture of ammonium sulfateand pancreas proteinase free from peptidase. The quantity of enzymes contained in the mixture is such as to be capable of liquefying 2.5 kilos of gelatine at 37 C. after an hour's action. After having been drenched, the skins are worked up in the usual manner. An excellent leather is thus obtained.

3. 20 kilos of limed and unhaired calf pelts are stirred in a bath consisting of lactic acid of to 1% strength until a test portion cut from the pelt only yields a slight red coloration with phenolphthaleine. The skins are then taken out of the bath, rinsed and treated with a drenching agent as indicated in Example 1. The quantity of ammonium chloride usually added may be reduced or even omitted.

I claim:

1. The process of drenching skins which consists in causing a solution of pancreas proteinases free from peptidases to act upon the skins.

2. The process of drenching skins whichconsists in causing a solution of pancreas proteinases free from peptidases containing an ad-- WILI-IELM NEUGEBAUER. 

